• 한국IT서비스학회:학술대회논문집
• /
• 2003.11a
• /
• pp.713-721
• /
• 2003

The time to market and productivity of embedded system needs a quality measurement process management of embedded software. But, defect management without preemptive analysis or prediction is not useful for quality measurement process management. This subject is focused on the defect that is one of the most important attributes of software measure in the process. Defining of defect attribute and quality measurement process management is according to understanding of embedded sw characteristics and defect data. So, this study contributes to propose the good method of the quantitative based on defect management in the test phase of sw lifecycle.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.2 s.140
• /
• pp.165-174
• /
• 2005

Recently, world leading companies on manufacturing field are trying to adopt a PLM methodology, which is a new production paradigm, for a survival and strengthening the competitiveness. Some projects for a digital shipyard including a methodology of a digital simulation framework are going on by Seoul national university and Samsung heavy industry. A Database methodology for a scheduling data, an interfacing methodology for a simulation input and output, and a synchronized simulation related methodology are required for enhancing the value of the digital simulation for shipbuilding. In this paper, such a methodologies and a related case study for a fabrication factory and an assembly factory are presented.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.43 no.4
• /
• pp.208-216
• /
• 2020

With the spread of smart manufacturing, one of the key topics of the 4th industrial revolution, manufacturing systems are moving beyond automation to smartization using artificial intelligence. In particular, in the existing automatic machining, a number of machining defects and non-processing occur due to tool damage or severe wear, resulting in a decrease in productivity and an increase in quality defect rates. Therefore, it is important to measure and predict tool life. In this paper, ν-ASVR (ν-Asymmetric Support Vector Regression), which considers the asymmetry of ⲉ-tube and the asymmetry of penalties for data out of ⲉ-tube, was proposed and applied to the tool wear prediction problem. In the case of tool wear, if the predicted value of the tool wear amount is smaller than the actual value (under-estimation), product failure may occur due to tool damage or wear. Therefore, it can be said that ν-ASVR is suitable because it is necessary to overestimate. It is shown that even when adjusting the asymmetry of ⲉ-tube and the asymmetry of penalties for data out of ⲉ-tube, the ratio of the number of data belonging to ⲉ-tube can be adjusted with ν. Experiments are performed to compare the accuracy of various kernel functions such as linear, polynomial. RBF (radialbasis function), sigmoid, The best result isthe use of the RBF kernel in all cases

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.2
• /
• pp.14-22
• /
• 2021

A plan for the development of reliability-based ROK amphibious assault vehicles is proposed. By analyzing the development case of the U.S. EFV, considerations for the successful development of the next-generation Korea Forces amphibious assault vehicle are presented. If the vehicle reliability can be improved to the level of the fourth highest priority electric unit for power units, suspensions, decelerators, and body groups, which have the highest priority among fault frequency items, a system level MTBF of 36.4%↑ can be achieved, and the operational availability can be increased by 3.5%↑. The next-generation amphibious assault vehicles must fulfill certain operating and performance requirements, the underlying systems must be built, and sequencing of the hybrid engine and the modular concept should be considered. Along with big-data- and machine-learning-based failure prediction, machine maintenance based on augmented reality/virtual reality and remote maintenance should be used to improve the ability to maintain combat readiness and reduce lifecycle costs.

• Journal of Internet Computing and Services
• /
• v.22 no.6
• /
• pp.59-69
• /
• 2021

Malfunctions and failures linked to medical devices may result in significant damage for human being. Thus, in order to ensure that safety of medical device is achieved, it should be established and applied the international standard. It is required to integrate and customize activities at standards, owing to reference relationship between standards, especially, activities based safety analysis is too expensive. This paper proposes a integration process that integrate activities of development lifecycle and safety process. Additionally, we derived a guidance based on STPA for integration process. As a result, we can be performed systematically from early stage of the development and increased effectiveness of integration process by the guidance.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2023.11a
• /
• pp.221-221
• /
• 2023

1969년에 발간된 API521 1st edition에서는 Flare Load 저감용으로 적용되는 HIPS (High Integrity Protection System)는 모두 Pressure Safety Valve의 고장확률보다 낮은 SIL 3 (Safety Integrity Level)등급을 적용할 것을 요구하고 있다. Flare Stack 저감용 HIPS는 주로 압축기 출력압력상승, Reboiler Steam 과다주입, 전력공급중단냉각펌프고장 등에 의한 Flare 발생을 예방하기 위한 기능을 가진 SIF (Safety Instrumented Function)로 구성된다. 하지만 2007년도 발간된 API521 5th edition에서는 LOPA (Layer Of Protection Analysis) 분석을 통해 Target SIL을 도출하는 것으로 요구사항을 변경했다. 이에 따라 이번 연구에서는 Flare Load에 가장 큰 영향을 미치는 시나리오 중 대표적인 시나리오를 대상으로 HAZOP(Hazard and Operability Study)과 LOPA분석을 실시해서 Target SIL이 어떻게 도출되는지를 연구했다. Flare Stack에서 Flare를 발생시키는 대표적인 시나리오들에 대해 LOPA분석을 실시한 결과 압축기 출력압력상승은 SIL 2, Reboiler Steam 과다주입은 SIL 3, 전력공급중단은 SIL 0, 냉각펌프고장은 SIL 0로 모두가 SIL 3 가 나오지는 않았다. SIF 설계 시 Target SIL을 만족시키는 것도 중요하지만 운전 시 SIL 등급이 계속 유지되게 하지 위해 인적오류, 시스템적 고장, 하드웨어고장 등에 의해 SIF 기능불능화가 되는 것을 예방하기 위한 기능안전관리시스템 (FSMS)를 적용하는 것도 중요하다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.5
• /
• pp.1301-1316
• /
• 2024

In modern warfare, missiles play a pivotal role but typically spend the majority of their lifecycle in long-term storage or standby mode, making it difficult to detect failures. Preemptive detection of missiles that will fail is crucial to preventing severe consequences, including safety hazards and mission failures. This study proposes a contamination-based stacking ensemble model, employing the local outlier factor (LOF), to detect such missiles. The proposed model creates multiple base LOF models with different contamination values and combines their anomaly scores to achieve a robust anomaly detection. A comparative performance analysis was conducted between the proposed model and the traditional single LOF model, using production-related inspection data from missiles deployed in the military. The experimental results showed that, with the contamination parameter set to 0.1, the proposed model exhibited an increase of approximately 22 percentage points in accuracy and 71 percentage points in F1-score compared to the single LOF model. This approach enables the preemptive identification of potential failures, undetectable through traditional statistical quality control methods. Consequently, it contributes to lower missile failure rates in real battlefield scenarios, leading to significant time and cost savings in the military industry.

• International Journal of Computer Science & Network Security
• /
• v.24 no.7
• /
• pp.1-10
• /
• 2024

Software architecture are High-level design decisions shaping a software system's components, structure, and interactions. It can be a blueprint for development, evolution, and ongoing maintenance. This research investigates the communication practices employed by software architects and developers to ensure adherence to the designed software architecture. It explores the factors influencing the selection of follow-up methods and the impact of follow-up frequency on successful implementation. Findings reveal that formalized follow-up procedures are not yet a ubiquitous element within the software development lifecycle. While electronic communication, particularly email, appears to be the preferred method for both architects and developers, physical and online meetings are utilized less frequently. Interestingly, the study suggests a potential confidence gap, with architects expressing concerns about developers' ability to faithfully implement the architecture. This may lead to architects providing additional clarification. Conversely, while most developers reported confidence in their software knowledge, overly detailed architecture documentation may pose challenges, highlighting the need for architects to consider alternative communication strategies. A key limitation of this study is the sample size, restricting the generalizability of the conclusions. However, the research offers valuable preliminary insights into the communication practices employed for architecture implementation, paving the way for further investigation with a larger and more diverse participant pool.

• Journal of the Korean Society of Systems Engineering
• /
• v.9 no.2
• /
• pp.23-36
• /
• 2013

Plant industry is one of technology-intensive and most prosperous industries in Korea because of its recent prosperity and promising outlook in export. However, no Korean EPC company has yet been well prepared in lifting their capacity sufficient enough to get the upstream conceptual or basic design and engineering orders for sizable plant projects which are known as the more value-added. If systems engineering, a methodology which developed complex systems such as airplanes and has been justified its effectiveness in Defense and NASA projects, can be integrated with plant engineering which should be developed and applied based on the requirements of so many stakeholders, conditions, lifecycle concepts, and constraints of the projects, huge synergic effect is expected particularly in developing a specific upstream design, which is a conceptual or basic design. The notion of integration with each other between systems engineering and plant engineering can be really the crux of EPC's success in any plant projects. This paper suggests an approach showing a methodology how to dig out, analyze, evaluate, verify and implement the stakeholders' requirements into a plant design in conceptual phase using the theory and skills of systems engineering. ISO/IEC 15288 well known systems engineering standards is used. Carbon capture system is used for a case study, for it is an emerging technology in reducing emissions of carbon dioxide causing global warming from flue gas after combustion. Here systems engineering was proven to play a substantial role in enhancing the capability of designers in developing a conceptual design of whole plant or certain part of crucial plant systems.

• Journal of Korea Multimedia Society
• /
• v.9 no.2
• /
• pp.226-233
• /
• 2006

With the advancement of the Internet, bulky information overflows in the Web. When the Internet user wants to get the necessary information, it is essential to use the retrieval system. It is not easy for the user to get the information from the result of the retrieval system. Various research activities have been advanced for the result improvement of the retrieval system. Although retrieval results can be improved with ontology, it usually takes lots of costs for users to construct the Japanese domain ontology. This paper discusses how to integrate search result refinement and domain ontology refinement using the domain ontology tool called Japanese DODDLE, and how to improve the research result using the constructed ontology. To prove the effectiveness of the suggested methodology, the case study with rocket operation is performed and it shows that the methodology can be promising.